[v6.1] WARNING: refcount bug in call_timer_fn

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: a3eb3a74aa8c Linux 6.1.80
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=14c76374180000
kernel config: https://syzkaller.appspot.com/x/.config?x=36414e87ed688c3e
dashboard link: https://syzkaller.appspot.com/bug?extid=078fb36c78e055e7f49c
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/16e5159a2916/disk-a3eb3a74.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/45345b2cd9e4/vmlinux-a3eb3a74.xz
kernel image: https://storage.googleapis.com/syzbot-assets/d65bd0282724/bzImage-a3eb3a74.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+078fb3...@syzkaller.appspotmail.com

------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 1 PID: 21 at lib/refcount.c:28 refcount_warn_saturate+0x14e/0x1a0 lib/refcount.c:28
Modules linked in:
CPU: 1 PID: 21 Comm: ksoftirqd/1 Not tainted 6.1.80-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
RIP: 0010:refcount_warn_saturate+0x14e/0x1a0 lib/refcount.c:28
Code: 0a 01 48 c7 c7 c0 d4 3c 8b e8 5e 9e 1a fd 0f 0b eb 8d e8 65 a1 52 fd c6 05 a6 4d 27 0a 01 48 c7 c7 20 d5 3c 8b e8 42 9e 1a fd <0f> 0b e9 6e ff ff ff e8 46 a1 52 fd c6 05 88 4d 27 0a 01 48 c7 c7
RSP: 0018:ffffc900001b7a08 EFLAGS: 00010246
RAX: cd91b964d3de7b00 RBX: 0000000000000003 RCX: ffff888012751dc0
RDX: 0000000080000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000003 R08: ffffffff81527e8e R09: ffffed1017324f1c
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: 1ffff92000036f48 R14: 0000000000000001 R15: 0000000000000100
FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6f2a261fe8 CR3: 000000000ce8e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
call_timer_fn+0x1ad/0x6b0 kernel/time/timer.c:1474
expire_timers kernel/time/timer.c:1519 [inline]
__run_timers+0x67c/0x890 kernel/time/timer.c:1790
run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1803
__do_softirq+0x2e9/0xa4c kernel/softirq.c:571
run_ksoftirqd+0xc1/0x120 kernel/softirq.c:934
smpboot_thread_fn+0x52c/0xa30 kernel/smpboot.c:164
kthread+0x28d/0x320 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
</TASK>


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